The new Environmental Protection Agency (EPA) tolerances were requested by Dow AgroSciences following the firm's expansion of its pesticide sulfuryl fluoride - trade name ProFume - which is used to fumigate food processing facilities and storage areas.
The product targets stored product pests, as well as those insects that may be transported from the field on food commodities. But some environmental groups argue that the new levels are potentially dangerous.
Indeed, the Environmental Working Group, Beyond Pesticides and the Fluoride Action Network (FAN) said that the maximum legal limits for the fluoride-based pesticide in foods have been set at levels that dwarf the amount allowed in tap water.
For example, the EPA is allowing 900 parts per million (ppm) of fluoride in dried eggs, as opposed to the maximum 4 ppm allowed in tap water. One third of the nation's eggs are sold and consumed in dried, reconstituted form.
The groups also noted that 900 ppm set for dried eggs is extremely close to that used in toothpaste (1,000 ppm), a level that is considered toxic if consumed in greater than pea sized portions.
"How can the EPA consider 900 ppm in eggs safe, while the Food and Drug Administration directs parents to call poison control centers if their children consume more than a pea sized portion of toothpaste with fluoride at 1,000 ppm?" asked Paul Connett, executive director of FAN.
"Unlike toothpaste, eggs are meant to be eaten, not spat out."
It isn't just powdered eggs that could contain dangerous but legal levels of fluoride under the new regime. Fluoride Action Network (FAN) researcher Chris Neurath claims that all processed foods will be allowed 70 ppm fluoride residues, including everything from breakfast cereal to cake mix.
"Wheat flour is allowed up to 125 ppm," he said. "For comparison, the maximum level of fluoride allowed in drinking water is 4 ppm and the natural level of fluoride in mothers' milk is approximately 0.008 ppm. The potential for a significant number of acute poisoning cases every year is very real."
Dow AgroSciences however believes that the establishment of new accepted fluoride levels is great news for millers and food processors. "With the label amendments and additional tolerances, ProFume brings unprecedented flexibility and effective, reliable control of stored product pests to more markets segments and broadens its use pattern," said Drew Ratterman,marketing specialist, Dow AgroSciences.
"We appreciate the continued support of many throughout the industry during this registration process and are pleased to be able to offer aproduct that meets their fumigation needs."
However Richard Wiles, senior vice-president of the Environmental Working Group (EWG,), contends that EPA is relying on outdated science to support this increase in fluoride exposure.
"In our view [the EPA] has not discharged its legal duty to thoroughly consider the effects of fluoride on infants and children, from all routes of exposure, based on a thorough review of the most recent peer-reviewed science," he said.